Input Output Games

Function Machine Game

A function machine follows one secret math rule. Send in test numbers, compare the outputs, and uncover the rule before you run out of rounds.

Play the Function Machine

Start with the example, run your own tests, then choose the rule that explains every output. Complete 5 rounds in each level to earn its badge.

How to Play

Find the Rule Like a Math Explorer

  1. Study the first clue

    Look at the input and output pair. Ask what single operation could connect them.

  2. Test your own numbers

    Enter an input you pick. Each new pair is evidence that rules out wrong answers.

  3. Compare before you guess

    Check every clue against each rule. Pick the operation that works for all of them.

Strategy tip: Test the same input with different thinking. If one clue could be "add 5" or "multiply by 2 and subtract 1", a second clue usually settles it. Two-step rules hide an operation inside another one.
Level Guide

Choose the Right Level

01

Level 1 · Add & Subtract

Best for Grade 2–3. Simple rules build confidence with the input output idea.

02

Level 2 · Multiply & Divide

Best for Grade 3–4. Practice fact families and inverse operations.

03

Level 3 · Two-Step Rules

Best for Grade 3–4. Follow rules such as "multiply by 2, then add 3."

04

Level 4 · Mixed Rules

Best for Grade 4–5. Every round mixes all the rule types to keep you thinking.

⚡

Challenge · 60 Seconds

Best for Grade 4–5. Use every strategy while the clock counts down.

Questions

Function Machine FAQ

How does the function machine game work?

The machine follows one secret math rule. You send in a test number, read the output, and use those clues to choose the rule. To be sure, test more than one number before you guess.

What if my students guess a rule that fits only one clue?

One pair can fit several rules, so encourage students to test a second or third number. A rule is only correct when it explains every output, not just the first one.

Is the challenge round timed?

Yes. The challenge level gives you 60 seconds to solve as many rules as you can. Every correct guess adds to your score and keeps your streak going.

Keep Practicing

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Play Devices Game

All Input Output Games

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